Apparatus for heating, thawing, and drying concrete aggregates



Sept. 12, 1933. A Q s JOHNSON 1,926,724

APPARATUS FOR HEATING, THAWING, AND DRYING CONCRETE AGGRBGATES Filed Dec. 10, 1930 Patented Sept. 12, 1933 e UNITED STATES",

PAT NT OFFICE,

APPARATUS FOR HEATING, THAWING, DRYING CONCRETE AGGREGATES Charles S. Johnson, Champaign, 111. Y

Application December .10, 1930 Serial No. 501,182,

'2 Claims. (01. 34-34) In the production of concrete, it is usual to keep a supply of theaggregates in an overhead bin having a dischargeopening or openings in 7 its lower portion through which theaggregates are discharged into a measuring or weighing batcher. The aggregates usually contain more or less moisture and therefore during cold weather the contents of the'bin are likely to freeze so as to interfere with the discharge of the material from the bin. Water collecting in the lower portion of the bin may'freeze into a solid mass. When freezing has occurred, it has been customary to thaw the aggregates by blowing steam into the bin, but this'has resultedin increasing the moisture content of the a gregates and has produced a liability to serious variations in the strength of the concrete. 7

The object of the present invention is to provide a method and 'means of heating and thaw-1 ing aggregates which shall be free from theobjections incident to increase in the moisture content of the aggregates and which shall at'the same time be more economical.

' attain by introducing into the lower portion of showing alterna construction, I have hereinillustrated a bin "'1' similar to the one shown in my Patent No. 1,754,516, dated April 15, 1930,v said bin being octagonal in horizontal cross-section-and being 'tapered toward its lower end. If desired, 'the bin may be pr'ovidedwithvertical partitions 2,v whereby the interior of the bin is divided into four compartments, each of said compartments having a discharge opening 3 at its lower end.

The meansfor controlling discharge through the openings 3 may be of any preferred character and therefore has been merely indicated diagrammatically herein by means of a dotted line 4.

Oneor more chambers are located within the lower portion of the bin to which hot gases may be supplied. Preferably, and as hereinshown;

four chambers 5 are provided at the angles formed between the partitions 2., These chambers are closed except for louvers 6, said louvers This object I "in various ways.

the accompanyin ployed for generating hot gases andfor supplying them to the chambers5. In Fig. 1 I have shown astove or furnace 7' having a flue 8 for the escape of. the products of combustion, said flue being connected to the suction side of a blower 9. The

outlet of the blower 9 is connected by means-of a pipe 10 to. a manifoldll from which pipes 12 extend to "the chambers 5. If desired, a shut-off valve 13'may be connected into each of the pipes 12so that any chamber may be shut off and so that the flow of gases may be regulated. An air inlet l4. maybe provided in the flue 8 sotha the hot gases maybe diluted, if desired. 1 When it is desired to heat, dry or'thaw the contents" of the bin, hot gases generated in the heater '7 are forced by means of the blower 9' into thechambers 5, whence the gases'escape aggregates in the bin. It will be seen that frozen aggregates will notonly be thawed and heated but also dried. Moreover, the heat is applied more economically; than whensteam is'used, because the heat losses involved inythe vaporization of water to form steam are avoided.

" .The apparatus shown in Fig. 1 may be modified Thus the blower 9 may be ,through the louvers 6 and permeatethe mass of I omitted and thehot gases allowed to flow through I ;the',chambers 6 under the pressure generated within the heater 7?, as indicated diagrammatically in Fig. 3. Fig. 4 illustrates another modifica tion employing an'oil burner 15 ofthe well-known type that comprises a fan 16 for supplying a relatively-large volume of air at low velocity to supportv the combustion "of oil.

1 I claim as my invention:

. 1. The combination of an imperforate bin having a discharge opening at its lower end and vertical partitions dividing the bin into a plurality of compartments all discharging through said open ing-and arranged around the central axis of the bin a chamber for .hot gases, adjacent-the said discharge opening, and at the center of the'bin,

and having louverscommunicating with the compartments to discharge hotgases therefrom into the bin and upwardly through the material'therefor supplying hotgases to said in, and means chamber. V I v 2.,The combination stated in claim 1', the chamice her for hot gases being divided by the partitions 1 into separate sections, and valve means tos'electively supply the separatesections with hot gases respectively.

1 CHARLES s. JOHNSON.

serving to permit the escape of gases into the aggregates that surround the chambers 5, while 1 at the same time preventing the aggregates from entering the chambers. i

Means of any preferred nature may be em- 

